Abstract: A device connected to a valve stem for controlling a valve of an internal combustion engine. The device includes a cam having a first peripheral contour and a disk having a second peripheral contour smaller than the first peripheral contour. A first rocker arm is pivotable on an axle mounted bearing based on the second peripheral contour of the disk. A compensation device is positioned between the first rocker arm and the valve stem for maintaining contact therebetween. A second rocker arm is pivotable on the bearing based on the first peripheral contour of the cam. A drive selectively couples the second rocker arm to the valve stem. The drive includes a radially displaceable spherical driver disposed within the first rocker arm. A locking slide includes an engagement surface which radially displaces the spherical drive into a spherical depression on the second rocker arm so that the valve operates based on the first peripheral contour of the cam.
Abstract: A valve drive for controlling gas exchange valves of an internal combustion engine having a cylinder head, a valve stem and a longitudinal tappet axis including a camshaft having a first cam with a first cam profile and a second cam with a second cam profile greater than the first cam profile. The second cam has two cam members which abut both sides of the first cam. A cup-shaped tappet is slidably disposed within the cylinder head for engaging the two cam members. A central tappet is disposed within the cup-shaped tappet for engaging the first cam. A lash adjuster is disposed within the central tappet and supported against the valve stem. A hydraulic switching arrangement is disposed between the cup-shaped tappet and the central tappet for selectively moving the valve stem according to the first and second cam profiles.
October 14, 1994
Date of Patent:
September 17, 1996
IAV Motor GmbH
Bertold Mayr, Leopold Muller, Joachim Bohme